Group / Channel Support

[CoryFoy]

Is your feature request related to a problem? Please describe.
With the newer versions of TAK Server Channel Support was added. It is unclear exactly how TAK Tracker handles Channel support, but we need to ensure that when connecting to a server we are communicating in the right channels

Describe the solution you'd like
As part of the settings select which channel to connect to

Additional context
iTAK and ATAK handle Channel support differently. When connecting to a server ATAK by default has all Channels turned off while iTAK by default has all Channels turned on. It's likely we would default TAK Tracker to have all Channels on and allow toggling so that the Tracker user will always show up somewhere when connecting to a server.